Polar BEAR (Polar Beacon Experiment and Auroral Research)

American military satellite designed to study communications interference
caused by solar flares and increased
auroral activity. The data from the mission complements data taken by its
predecessor, HILAT. The core vehicle was a Transit navigational satellite
retrieved from the Smithsonian's National Air & Space Museum where it had
been on display for 8 years. Polar BEAR's Auroral Imaging Remote Sensor
imaged the aurora borealis and its Beacon Experiment monitored ionospheric
propagation over the poles.